The invention relates to an electric restoring switch comprised of a button that allows actuation about an eccentric axle and carries at least one link that transfers the actuation, and of a contact spring which is arranged in a housing supporting electric connectors and features a notched contact tongue.
Known from DE-GM 71 38 974 is an electric restoring switch in which a bearing for the pivot axle of the button is arranged eccentrically and above a contact rail. The button features a link that acts on an elastic contact tongue of a contact spring, which contact tongue is notched out of the elastic contact spring. The contact spring is arranged approximately perpendicularly to the button in the housing. It has only one fixed bearing about which it pivots under the effect of the link contained on the button, as the button is actuated. The contact tongue is responsible for the position of the button and for the necessary contact force. This configuration necessitates a large-area design of the housing bottom and that the contact spring has a complex shape, so as to assure resetting as well as the contact force. Heat buildup due to the flow of current through the contact spring, however, will cause the spring force to diminish and the superficial forward resistance to increase, leading to a temperature buildup.
Furthermore, DE 34 21 021 C2 discloses an electric restoring switch with a button to which two links are molded symmetrically, between which a cam is fitted which alternately plunges in two depressions of a contact spring, thereby causing the contact spring to pivot to its opposite position. The two links are elastic and shaped, on their sides facing the cam, in such a way that the cam returns upon completed actuation again to its zero position. This configuration of the link and of the cam is relatively expensive and requires great accuracy in their manufacture. The recoil of the cam depends on the spring properties of the plastic material, and thus on its fatigue strength.sup.1. FNT .sup.1 Translator: "Halterungsbedtandigkeit" durability as a holding device! appears to be a typographic error; proper term is presumably "Alterungsbestandigkeit" fatigue strength!